Muscle morphological changes and enhanced sprint running performance: A 1-year observational study of well-trained sprinters.

Numerous cross-sectional studies have attempted to identify the muscle morphology required to achieve high sprint velocity. Our longitudinal study addressed an unanswered question of cross-sectional studies: whether hypertrophy of the individual trunk and thigh muscles induced by daily training (e.g.

The field study about the effects of artificial CO-rich cool-water immersion after outdoor sports activity in a hot environment.

Background/objective: In our previous laboratory experiment (room temperature of 25 °C), CO-rich cool-water immersion (CCWI) suppressed subjects' core body temperature even during repeated exercise. It is unclear whether the suppression of body temperature elevation would also continue after CCWI in a hot outdoor environment. Herein we investigated the thermal effects of CCWI after regular exercise training in heat on subjects' core temperature (T), three skin temperatures (T), heart rate (HR), and the rate of perceived ice (RPI).

Agonist-antagonist muscle activation during drop jumps.

Pre-programmed and stretch-induced muscle activities of agonist muscles can play important roles during stretch-shortening cycle exercises. It is still not clear how the antagonist muscles function when the drop and rebound intensities are varied during drop jump (DJ) exercises. The purpose of the present study was to examine the regulation of agonist-antagonist muscle activation during DJ with different drop and rebound heights.

Relationship between peak VO2 and subcutaneous fat thickness of the thigh measured by ultrasonography.

Background: Measured physical activity and percent body fat obtained by bioelectrical impedance analysis have been used as indicators of cardiorespiratory fitness in middle-aged women and children. However, the relationship between subcutaneous fat thickness in various regions of the thigh determined by ultrasonography and cardiorespiratory fitness has not been previously reported.

Methods: We measured subcutaneous fat thickness in the frontal, lateral, and medial regions of both thighs using ultrasonography, and also determined peak VO2 and percent body fat in 13 healthy and generally well female college students.